Gunther Holtorf and his wife Christine on a 500,000 mile journey around the world

The Son Doong Cave in Vietnam is the biggest cave in the world. It's over 5.5 miles long, has a jungle and river, and could fit a 40-story skyscraper within its walls.

15 cheap dream vacations you can actually afford

"Drives of a Lifetime: 500 of the World's Most Spectacular Trips" by National Geographic

If you're planning a trip, check out these standout sites to get the best deal possible on your flight.

35 Places to swim in the world's clearest water

Cheap travel

Trademark Fine Art Typography World Map III by Michael Tompsett Canvas Wall Art, 22x32-Inch by Trademark Fine Art,

Wonderland in Texas!

THE DREAM! - How to drive across the USA hitting all the major landmarks. 12,225 miles. Click to see time-lapse drive across America in 5 minutes, hitting major landmarks.

Things to Do in Peru - 10 Day Itinerary

Starfish Beach, Grand Cayman

I will travel the world....checking 'em off the list!

Mexico--near Chichen Itza--an awesome place to stop for a swim

Awesomeness from places around the world

Explore the caves of Hang Son Doong, Vietnam, part of a network of over 150 caves. Surrounded by jungle and used in the Vietnam war as a hideout from American bombardments, the cave passage is so large that it could hold a block of 40-storey skyscrapers.

car camping

Road trip to Joshua Tree National Park, California #JoshuaTree #JoshuaTreeNationalPark #California #Desert #SoCal

World's deepest indoor diving pool, Belgium

Krubera Cave (deepest cave in the world) in the Western Caucasus